Vernier caliper radii attachment



May 4, 1948. G. PODOLAN VERNIER CALIPER RADII ATTACHMENT I Filed Oct. 25, 1944 I "II R. W mm m M MV 0 V. B 5 0 a Patented May 4, 1948 UNITED STATES omen 2 Claims. (Cl. 33-159) My invention relates to a new and useful improvement in a Vernier caliper, and more particularly to an attachment for converting the caliper to a divider. It is an object of the present invention to provide a caliper of the Vernier type with an attachment that can be readily attached" or detached to the tongs or prongs of the caliper in a manner which will permit reading the same scale on the caliper.

It is another object of the present invention to provide an attachment which can be fixedly secured to the tongs or prongs of the caliper for converting the same into a rigid beam compass scriber or divider. I

It is another object of the present invention to provide a, device of this class which will be simple in structure, economical of manufacture, rigid in construction and highly eficient m use.

Other objects will appear hereinafter.

It is recognized that various changes and modifications may be made in the detail of structure illustrated without departing from the invention itself, and it is intended that such variations and changes shall be encompassed within the scope of the claims which form a part of this specification.

Forming a part of this specification are drawings in which,

Fig. 1 is a plan view of the caliper with the invention attached;

Fig. 2 is a cross-sectional view taken on line 2--2 of Fig. 1;

Fig. 3 is a fragmentary cross-sectional view taken on line 3-3 of Fig. 2;

Fig. 4 is a cross-sectional view of a modified form of the invention.

Referring to the drawings, there is shown a bar II! having a, tongue or prong II formed integral therewith and extending at right angles thereto. The bar I is provided with a scale I2. Slidably mounted on the bar I0 is a vernier slide I3 having a tongue I6 which extends in alignment and parallel with the tongue I I. The slide I3 is provided with an opening I4 forreading the scale l2. Markings I are provided on the slide I3 for cooperative reading with the scale I2. An anchor slide 20 is slidably mounted on the bar I0 and is tied to the slide I3 by means of a threaded stud I! which is anchored on the block I3 and projects through the anchor slide 26. A nut 2| is carried by the anchor slide 20 and is threaded on the stud I1. The bar I3 and slide 26 may be secured stationary on the bar III by set screws I 8 and 22 respectively. The

tongues II' and I6 are each provided with fac ings 2'5. In normal use, the caliperis read with the object that is to be scaled placed between the tongues II and I6 against their faces 25.

Each of the tongues II and I6 is formed alike so-tha't a description of one, it is believedywill sufiice for both. The'face of the prong, opposite the face 25, is cut away to provide the arcuate face 21 and the planar face 28. A marker 40 is placedagainsta face 25 and held thereto by a band 34 which also encircles the tongue. Se

cured by pin33 inthe'band 34is a block 30, a face of'which is formed in an arcuate section 4| for engagement with the arcuate portion 2'1.

Formed onthe block *3Il isa projection3l for engagement with the face 28. A- projection 32 is formed on the block 30 and adapted to engage one face of the prong I6. A spring 38 is disposed in a bore 31 formed in the block 30, one end of which engages the pin 33 and its opposite end engages the bore 31 for moving the block 30 against the thickened end 35 of the band 34. A set screw 36 is threaded through the thickened portion 35 of the band 34 for engagement against a block 30.

It will be noted that by the present arrangement of parts, the caliper can be quickly and easily converted for use as a divider or beam compass scriber by merely loosening screw 36 and removing the marker and band. Likewise, its attachment is easily and quickly made by fastening of screw 36. The block 30 is at all times carried by the band 34 so as to facilitate its attachment to the caliper. A slot 4| is formed in the block 30 to permit movement of the block about the pin 33. In attaching the device, the user can, by

merely holding in one end the marker and band,

slide the assembly onto the end of the prong. The block 30 will be, by action of the spring 33, moved outwardly against the end of the band and away from the steps 21 and 28 until the assembly has been fully slid on the prong, whereupon the tightening of the screw 36 will move the block against the tension of the spring 38 to engage the steps and frictionally lock the assembly upon the prong. By the use of the faces 21 and 28, the assembly cannot creep on the prongs, thereby permitting the user to apply pressure upon the caliper without fear that the markers 25 will slide when it is used as a beam compass scriber or as a divider against an object that is to be measured or scribed. It will be noted that, if desired, the calipers can also be used for obtaining inside measurements by the use of the present attachment.

To further facilitate manufacture, the lower step 28, if desired, may be radiused as shown in Fig. 4 to engage a V-groove formed in the lower step of the section 3| in the block 30. This arrangement permits an easier alignment of the parts.

What I claims as new is:

1. In a caliper of the class described, an elongated bar; a prong carried by and projecting outwardly from one edge of said ban a marking instrument engaging, one. face or Said prongiand projecting beyond said prong and the opposite face of said prong being cut away to provide planar faces meeting an arcuate face; a, band encircling said prong and saidmarkinginstrlirv I ment for clamping said marking instrument against the prong; a block positioned within said band and having a slot formed therethmugh connecting with a passage extended at substantially right angles to said slot; a pin projected: through outwardly from one side ofsaid bar; a marking instrument engaging oneiace'ofsaid prong and projecting beyond the end of'said' prong, the

4 with an arcuate face; a band encircling said prong and said marking instrument for binding the same together; a block positioned within said band and lying between one side thereof and said prong, said block having an arcuate face and planar faces for ngaging corresponding faces on said prong, said block having a passage formed therein and provided with a slot formed therethrough at right angles to said passage; a pin prolected throfigh said band and said slot, said pin being or less diameter than the width of said slot for permitting movement of said block on said pin relatively to said band within the limits of; said slot; and a spring positioned in said passage and engaging at one end with said block and -a'tsthe opposite end with said pin for normally resisting movement of said block on said pin in one direction.

' GEORGE PODOLAN.

BEEERENCES CITED The following references are of record in the file-of'this patent:

c lm ST TES PATENTS OTHER REFERENCES Bublication, American Machinist, page 142, Dec. 20,, 1945.

Publication, American Machinist, page 369,

face 'ofi saidprong opposite said engaged face 357 1929? being cut away to provide planar faces meeting 

